Live Plants in a freshwater aquarium are a great addition to most tanks. Unfortunately there is a lot of information out there and it can be tough to figure out what all you really need to do to successfully grow live plants.
I have always kept pretty basic, low tech planted tanks. I have just never gotten in to CO2 gas, super intense lights, soil substrates, etc. This article will take you right up to the point of taking that step in to going high tech, but if you and your tank truly grow to that point you will probably need some more advanced resources than this one article.
The most important thing to understand with live plants is that everything needs to be kept in balance. Lighting, nutrients, temperature, and CO2 all need to be kept in balance. It will never be perfect, but doing more of one because another is lacking will only keep things more out of balance. You will always have a limiting factor in the tank. As you and the tank progress this limiting factor will change.
When you first start with live plants your limiting factor will probably be lighting. Most standard light fixtures will have nothing more than one or two standard output bulbs. This can be enough for the most basic plant tanks, but most likely you and your tank will outgrow the basic lights pretty quickly. Upgrading to something along the lines of a 4 bulb HOT5 fixture is ideal. For a complete explanation of all things lighting, please read the Guide to Lighting an Aquarium.
As you increase your light the balance will need more nutrients. I would start with two things: root tabs and a general liquid fertilizer. I like Seachem Flourish Root Tabs. Just follow the directions, they will turn any substrate in to one with the nutrients needed for root feeders like swords. This will work with inert substrates such as the Estes Marine Sand (aka Stoney River and Ultra Reef) that I recommend for almost any tank.
As for the general liquid fertilizer I prefer either Seachem Flourish Comprehensive Supplement or AquaVitro Envy. AquaVitro is a top shelf company line made by Seachem that is not available online (the company will not sell to anyone who tries to sell it online). AquaVitro products are very good and definitely a great, high end option for planted and reef tank supplements. At this point the general additive should be all that you need.
Start with less of the general fertilizer than you think you need, the system isn’t used to the extra nutrients so you need to give it time to adjust. This means you may just be adding a little each week. This is best done after a water change so that you don’t remove it with a water change and you add some good stuff since that is when there will be the least amount of nutrients in the tank in general.
Don’t just add supplements if you don’t see a difference. If you start to add fertilizer twice weekly instead of once and after a month or so see no improvement, step back down to once weekly, that is not your limiting factor.
At this point the tank’s limiting factor may be one of a few things. It may be iron, CO2, light, etc. At this point it is appropriate to break my rule of only testing nitrate. Now you can start looking at the things known to limit plant growth: nitrate, phosphate, iron, GH, KH, and CO2. In most tanks there will be enough nitrate and phosphate, but they are worth checking. If the tests show something is inadequate then buy a supplement for that specific chemical and dose as needed. Start with half of what you need, it is easier to add more than to take any out. Again, the system isn’t used to the extra nutrients and the plants need to adjust to start taking advantage of it. Test frequently when you start dosing something new. Once you get it figured out you can back off the testing a little and just test periodically to see if the tank’s needs have changed.
I personally do not like to use CO2 gas. Even the best systems can fail on and administer too much CO2. This can cause a pH crash and kill everything. My tanks are fish tanks first, plant tanks second. To me this means I will not do something to benefit the plants that is a risk to the fish. If you choose to add CO2 gas make sure you have a good system, step up the use slowly, and only do what is needed to make the difference for the balance of the tank.
Seachem Flourish Excel is a liquid carbon source. When I tried it I had some cabomba grow approximately 4″ in 24 hours. Obviously carbon was the limiting factor in my tank at that time. As always start with less than you need. Be aware though, Excel is not just another fertilizer, it can be toxic (to you and other life) so do some research before jumping in to it. There are certain plants, inverts, etc. that it should not be used with at all.
Carbon Filter Media:
Be aware that carbon will remove chemicals, including your fertilizers. Any tank should be well maintained enough to not need carbon so you should be able to simply ditch it completely. The main things it removes are odor and discoloration, both of which are kept under control with adequate water changes.
Most people will say that the ideal filter for a planted tank is a canister since it will have minimal surface agitation which can drive off CO2. Again, my tanks are fish tanks first so I stick with HOBs and even use air stones. If you decide to go beyond what I do with my tanks then yes, a canister will be ideal. Any filter needs to be well maintained, at least once per month. Even if the tests show everything is good, in order to keep it that way you need to stay on top of the maintenance.
At the end of the day almost all tanks need some algae control, and planted tanks are even more likely to since you are promoting photosynthetic life. Keeping things in balance will help immensely. In addition to this though, you may need to hire some 24/7 labor to keep the algae in check. My top picks are bristlenose plecoes since they will not bother plants but will eat almost any type of algae. In very small tanks and when brown algae is the problem otocinclus are a great option. (Brown algae is usually eliminated by replacing the light bulbs and/or getting a more intense light fixture since brown algae is a low light algae.) If black hair algae is the problem then get some Siamese algae eaters. Flying foxes are commonly sold as Siamese algae eaters, but you can identify the Siamese algae eaters since they have a zig zag edge to their black line and the black line extends in to the tail. Don’t simply add fish as your way of controlling algae. They can certainly be part of the solution, but figuring out what is out of balance is a vital part of the solution.
Water changes are something that many planted tank keepers begin to slack on because the live plants can help water quality, particularly nitrate. It is possible for well balanced planted tanks (lots of plants and a low bioload of fish) to have little to no nitrate. However, since nitrate is not the only bad thing that builds up and lowers water quality, you still need to maintain a good weekly water change schedule. Even if the tests show everything is fine, you need to do weekly water changes of at least 25%. This will help guarantee that the water quality never becomes a problem.
I tried all sorts of plants over the years. I did not follow the usual rules of sticking with low light, medium light plants, etc. I just tried what I liked and 95% of the time it went very well. I am sure many of them would have done even better under the perfect conditions, but I am not worried about perfect. If a plant lives but doesn’t grow as quickly, isn’t as full, etc. I am okay with that.
It isn’t a bad idea when you are first starting to stick with some low light plants, so they will have the best chance of settling in well. Then, once you get the basics figured out, you can start trying different plants that you like and worry less about their perfect lighting preferences.
Low Light Plants/Good First Plants:
- Java Fern
- Crypts (also grows well on driftwood, not just in the substrate)
- Anubias (also grows well on driftwood, not just in the substrate)
- Tiger Lotus, both Red and Green (I love these plants)
Avoid java moss, it can get out of control. At first you won’t mind, you will just be happy something is living and doing pretty well. But as it gets out of control it can be tough to get rid of. It can get to the point of clogging filters, it isn’t fun. Don’t mess with it. Be aware that some moss balls are just balls of java moss, not true moss balls. I have seen this at Petco and I believe at Petsmart, so beware.
There are lots of lists and guides online, I encourage you to check them out just to get an idea of the order of plants you should try before others, just don’t avoid medium or even high light plants until you try them, you never know how well they will do for you.
With live plants comes the very real (and likely) risk of introducing pest snails to the tank. If you have a planted tank you will almost certainly bring in snails sooner or later. Even if you carefully inspect every leaf of every plant you buy before you add it to your tank you can easily miss a whole cluster of eggs. Some people go as far as bleaching their plants or dipping them in various prophylactic treatments such as alum or potassium permanganate. I have never done this, it seems a bit paranoid to me. The few pest snails I have seen over the years I removed manually.
Nerite snails are becoming quite popular and are a great, plant safe snail to help with algae in a planted tank. They stay relatively small and come in a wide variety of patterns (mostly green or brown base with black markings). In addition, they need brackish water to reproduce, so they will not take over a freshwater tank.
Malaysian trumpet snails are great at helping to keep the substrate aerated and clean. I haven’t found them to be necessary with the Estes sand I recommend, but it certainly won’t hurt to have them (especially if you don’t have fish that dig through the substrate such as goldfish or cichlids). Some people don’t like them because their population can get out of control, but I haven’t found this to be true in clean tanks that are not overfed.
Controlling snails once they are already in can be a bit of a headache. The simplest solution is manual removal, but if there are too many or they just never seem to stop showing up more aggressive actions need to be taken. Be aware that if you also have snails you want to keep manual removal is generally your only option. Loaches are great at eating snails, they love them. Assassin snails are another option, if you can find them. I generally like fish, including loaches, so I will usually just add a trio of a nice looking loach that is an appropriate size for the tank (some loaches get too large or rambunctious). Be aware that clown loaches have been known to eat holes in plants (they also get huge, so they should be avoided in most tanks anyways).